fix: validate alias attribute in PresenterCompilerPass

Add validation to ensure services tagged with 'flasher.presenter' have
the required 'alias' attribute. Previously, accessing $attributes['alias']
without checking would throw an "Undefined array key" error.

Now throws a clear InvalidArgumentException with a helpful message.

src/Symfony/DependencyInjection/Compiler/PresenterCompilerPass.php

@@ -20,6 +20,13 @@ final class PresenterCompilerPass implements CompilerPassInterface
 
         foreach ($container->findTaggedServiceIds('flasher.presenter') as $id => $tags) {
             foreach ($tags as $attributes) {
+                if (!isset($attributes['alias'])) {
+                    throw new \InvalidArgumentException(\sprintf(
+                        'Service "%s" tagged with "flasher.presenter" must have an "alias" attribute.',
+                        $id
+                    ));
+                }
+
                 $definition->addMethodCall('addPresenter', [
                     $attributes['alias'],
                     new ServiceClosureArgument(new Reference($id)),

tests/Symfony/DependencyInjection/Compiler/PresenterCompilerPassTest.php

@@ -54,4 +54,18 @@ final class PresenterCompilerPassTest extends TestCase
 
         $this->assertCount(0, $definition->getMethodCalls(), 'No method calls should be made when no tagged services exist.');
     }
+
+    public function testProcessThrowsExceptionWhenAliasIsMissing(): void
+    {
+        $definition = new Definition();
+        $this->container->setDefinition('flasher.response_manager', $definition);
+
+        // Register a service without the required 'alias' attribute
+        $this->container->register('presenter_without_alias')->addTag('flasher.presenter');
+
+        $this->expectException(\InvalidArgumentException::class);
+        $this->expectExceptionMessage('Service "presenter_without_alias" tagged with "flasher.presenter" must have an "alias" attribute.');
+
+        $this->compilerPass->process($this->container);
+    }
 }